The invention relates to basket devices of an open wire construction in which work pieces are carried for heat treatment in furnaces typically at temperatures to 2300 degrees F. Because of the extreme heat environment in which the baskets are utilized and due to the fact that the baskets are often stacked upon each other in the furnace, heat and load distortions on the baskets is a problem to which considerable attention need be given. When the basket becomes distorted the sides and ends may sag, rendering the stacking of the baskets unstable. The work pieces often become relocated and bunched in the basket. Under such conditions, the life of the basket is considerably shortened.
Heretofore, work handling baskets for high temperature furnaces have been fabricated by welding together in crossing relation suitable forms of heavy wound or flat strips of wire. Typically baskets include some form of a stacking brace on opposing basket sides which permits the baskets to be stacked and holds them in place such as in U.S. Pat. No. 2,807,454. However, the problem exists that the contacting surfaces of the stacked baskets do not evenly distribute the basket load and distortion of the basket occurs. This distortion normally results in the sides of the basket sagging inwardly and the ends of the basket sagging inwardly or outwardly. Thus, the stacking configuration of the baskets becomes wobbly and unstable.
Accordingly, an important object of the present invention is to provide a work handling basket for high temperature furnaces in which basket distortion due to ununiform load distribution is substantially reduced.
Yet another important object of the present invention is to provide a furnace basket for heat treating work pieces which permits maximum loading with minimum basket weight without adversely affecting the life of the basket.
Still another important object of the present invention is to provide a furnace basket for heat treating of work pieces which provides total perimeter contact and load bearing between stacked basket surfaces.
Still another important object of the present invention is to provide a high temperature furnace basket having stacking devices which permit stacking and interlocking of the baskets when the baskets are inverted in a top-to-top configuration as well as permits normal stacking of the baskets in a bottom-to-top relationship.